Arcing guard



1935. J. T. LUSIGNAN, JR 2,022,863

ARCING GUARD Filed NOV. 1, 1934 INVENTOR J05PH TL z/j/a/wl/vdig Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE ARCING GUARD Application November 1, 1934, Serial No. 750,944

10 Claims.

This invention relates to arcing guards for insulators and electrical conductors, and has for one of its objects the provision of a guard which will prevent an are over an insulator from strik- 5 ing the conductor and from injuring the insulator.

A further object of the invention is to provide a guard which shall be economical to manufacture and which will not add unnecessarily to the weight supported by the insulator.

10 A further object of the invention is to provide a guard which will extend along the conductor a suiiicient distance to protect the conductor from arcs which are spaced from the insulator string and yet will not reduce the clearance between 15 conductors more than is necessary.

A further object of the invention is to provide a device of the class named which shall be of improved construction and operation.

Other objects and advantages will appear from 20 the following description.

The invention is exemplified by the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly 25 pointed out in the appended claims.

In the drawing:

Fig. 1 is an elevation of an insulator string showing one embodiment of the present invention applied thereto.

30 Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is an elevation of the invention as applied to a dead end insulator.

In high potential transmission lines, and par ticularly in lines using hollow conductors, it is 35 of great importance to protect the conductor from arcs caused by flashover of the insulators. It is also desirable to prevent the are from striking into the insulator string. Heretofore rings or other arcing guards have been placed above the conductor at the bottom of the string for the purpose of preventing arcs from striking the conductor, and also for the purpose of modifying the potential gradient in the string so as to relieve the lowermost units of the string from over- 5 stress. Where a ring is used for this purpose, it

' is necessary to provide arms for supporting the ring and to make the ring of sufiicient diameter to locate the are away from the insulator string. A ring of such diameter tends to reduce the clearance between the conductors. The present invention avoids these objections without sacrificing any of the advantages of an arcing ring.

As shown in the drawing, the numeral l0 designates the units of an insulator string for supporting a conductor H. A clamp I2 is secured Cir to the conductor and carried by a fitting l3 supported from the lowermost insulator H). The upper end of the insulator string is carried by any suitable supporting structure and is provided with an arcing horn [4 extending in the vertical 5 plane of the conductor and having its ends l5 spaced sufiiciently away from the insulator string and extending downwardly a sufficient distance to maintain the are clear of the string in case of fiashover. An arcing guard I6 is secured to the 10 fitting I3 and comprises a pair of loops I'I extending along the conductor II at each side of the string of insulators Ill. The guard is made of a single bar of metal, preferably an iron pipe, for economy and convenience of manufacture. The two loops are connected by a central portion [8 which is flattened and perforated at l9 to provide holes by which it is bolted to the fitting l3. The two arms of each guard diverge toward the outer end of the guard; the outer ends of the two arms of each loop being connected by an arcuate portion which crosses above the conductor at the extreme end of the loop so as to insure protection of the conductor from being struck by the arc. In case an arc is diverted laterally relative to the conductor by a transverse wind, it will not be dislodged from the guard but will follow the guard around the curve at one side or the other of the vertical plane of the conductor. The guard forms its own supporting arms so that separate arms are not required and each loop supports itself'from the fitting at the lower end of the insulator string. The fact that the guard arms converge toward the string does not interfere with the eificiency of the guard for the reason that where the arms are close together, the conductor is additionally protected by the supporting clamp I2. Beyond the end of the clamp l2, the guard is wide enough to avoid any danger of the are passing the guard and striking the conductor. 40 The guard has its maximum width at points spaced away from the insulator string where the arcs terminate and where maximum protection of the conductor is required. By this arrangement, the maximum clearance between conductors, without sacrifice of arc protection, is secured.

In the form of the invention shown in Fig. 3, the numeral 20 designates a dead end insulator attached to any suitable support for holding the end of the conductor H). A jumper 2| extends from the conductor ID to a continuation thereof at the other side of the supporting structure or to any other device to be connected to the conductor [0. In this form of the invention a single arcing 5 guard 22 is employed attached to the fitting 23 at the end of the insulator string and between the string and conductor Ill. The guard 22 is in the form of a loop extending upwardly in the path of an are between the supporting structure and the conductor H). The single guard at one side of the conductor is all that is required in the case of a dead end insulator since the shorter striking distance is above the insulator, due to the downward inclination of the insulator. Furthermore, the jumper 2| acts as a shield at the lower side of the insulator string, and assists guard 22 in modifying the potential gradient of the string so as to relieve the line units of overstress.

I claim:

1. An arcing guard for an electrical conductor, which conductor is connected by an insulator to a support, said guard comprising a loop shaped member disposed in the arcing path between said conductor and said support and entirely at one side of the plane normal to said conductor at the point of intersection of said conductor with the axis of'said insulator, said guard having its point of maximum width spaced away from said plane and having a portion of less width than maximum adjacent said plane.

2. An arcing guard for an electrical conductor,

the conductor being suspended from a support by an insulator string and by a fitting connecting said conductor to said string, said guard comprising a metal bar bent into a loop, said bar being attached to said fitting to support said loop, said loop having its portion of maximum width spaced away from said fitting and having a portion of less width than maximum adjacent said fitting, the entire loop being disposed at one side of a plane passing through the axis of said insulator.

3. An arcing guard for an electrical conductor, which conductor is suspended from a support by an insulator string and by a fitting connecting said conductor to said string, said guard being positioned above said conductor and comprising an elongated loop shaped member having its major axis extending in the vertical plane of said conductor, said member being supported at one end thereof by said insulator string and being disposed entirely at one side of the'vertical plane normal to said conductor at its point of intersection with the axis of said conductor.

4. An arcing guard for an electrical conductor, the conductor being suspended from a support by an insulator string, said guard comprising a pair of elongated loop shaped members arranged one at each side of said insulator string, each member having its greatest width at a point spaced alongsaid conductor away from said insulator string and being supported at one end thereof on the lower end of said insulator string, said loop shaped members being disposed above said conductor with their major axes in the Vertical plane of said conductor and the outer extremities of said loop shaped members crossing said plane above said conductorQ 5'. An arcing guard for an electrical conductor, the conductor being suspended from a support by an insulator string, said guard comprising a pair of elongated loop shaped members each having one end thereof attached to said insulator string above said conductor and having the major axis thereof lying inthe vertical plane of said conductor, said loop shaped members having a maximum width adjacent their outer ends and being tapered inwardly toward the insulator string and. having arcuate portions at the outer ends crossing the vertical plane of said conductor above 5 said conductor.

6. An arcing guard for an electrical conductor, the conductor being supported by an insulator string and by a clamp connecting the conductor to said string, said guard being carried by said string between the lower end of said string and said conductor and comprising a pair of elongated loop shaped horns disposed at opposite sides of said string and having their major axes extending in the vertical plane of said conductor, said horns being inclined upwardly at their outer ends and having arcuate portions at their outer ends crossing the vertical plane of said conductor, said horns being of maximum width at points beyond the end of said clamp and being tapered inwardly toward said insulator string immediately above said clamp.

'7. An arcing horn for a conductor, which conductor is supported by an insulator, said horn comprising a single bar bent into an elongated loop and supported by said insulator at one end ,of said loop, the major axis of said loop extending in the direction of said conductor away from said insulator, said bar being bent in arcuate form to cross'said conductor at the outer extremity of said loop.

8. An arcing guard for a conductor, which conductor is supported by an insulator and attached by a clamp to said insulator, said guard comprising a pair of horns, each horn being a single bar bent into an elongated loop and supported by said bar at one end of said loop, said loop having its major axis extending along said conductor, the bar being bent in arcuate form to cross said conductor at the extremity of said loop opposite said insulator.

9. An arcing guard for a conductor, which conductor is supported by a fitting carried by a suspension insulator, said arcing guard being carried by said fitting above said conductor and comprising a pair of loop shaped arcing members, one at each side of a plane normal to the axis of said conductor and containing the axis of said insulator, each of said loop shaped members comprising a peripheral bar secured at the 5 outer edge of said member to said fitting, the peripheral members of the two loops forming an arcing guard shaped like a figure eight and sup- 7 ported at the neck or middle portion thereof by said fitting and having its maximum width at portions spaced from the axis of said insulator along said conductor and above the same so as to intercept discharge arcs which might strike said conductor.

10. An arcing guard for a conductor, which 69 conductor is carried by an insulator, said guard comprising a bar bent into a loop,said bar being attached at one side of said loop'to said insulator, curved portions of the periphery of said loop being bent about an axis spaced a material distance from'and disposed at one side of the axis of said insulator so that said loop has a portion of'maximum width spaced a material distance away from the axis of said insulator, said loop having a portion of less than maximum width nearer said in- 70 sulator than said portion of maximum width.

JOSEPH P. LUSIGNAN, JR. 

